The invention pertains to a method for simultaneously adjusting the camshafts of various cylinder banks of an internal combustion engine to predetermined nominal angles relative to the crankshaft, where the camshafts actuate the intake and exhaust valves of the associated cylinder banks of the internal combustion engine. The invention also pertains to an internal combustion engine with at least two banks of cylinders and a valve control system for each cylinder bank, each with at least one camshaft for the actuation of the exhaust and/or intake valves of the associated cylinder bank. In each case a camshaft adjuster can adjust the angle of at least one camshaft of a cylinder bank with respect to the crankshaft of the internal combustion engine. A control unit is provided which carries out the adjustment of the camshafts as a function of a predetermined nominal value.
In internal combustion engines with several banks of cylinders, such as the valve-controlled multi-row engine known from DE 198 32 383 A1, in which each row has its own set of camshafts, the angles of which are adjusted by a camshaft adjuster with respect to the crankshaft, a problem is observed at the low operating temperatures which can occur during, for example, a cold-start phase, namely, the problem that the camshafts of the different cylinder banks are adjusted at different speeds. This, however, leads to undesirable differences between the angles of one or more camshafts relative to the crankshaft and the angles of other camshafts relative to the crankshaft. For this reason, adjustment of the camshafts is not allowed until after the internal combustion engine has reached normal operating temperature.
A camshaft adjustment system is known from U.S. Pat. No. 5,462,022, in which a desired angle is automatically maintained between the camshaft and the crankshaft.